Error using mysql_num_rows

Question

Hi, Im trying to do a search engine. However, im facing this errors.. Anyone can help..

Error :

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\wamp\www\i-document\search_admin.php on line 90

Thankz in advance.

Php Code :

<?php

//Get data    

$button = isset($_GET['submit']) ? $_GET['submit'] : '';          
$search = isset($_GET['search']) ? $_GET['search'] : '';       
$find = isset($_GET['find']) ? $_GET['find'] : '';      

if (!$button)
  echo "You didn't submit a keyword.";  
else  
{  
  if (strlen($search)<=1)  
    echo "Search term too short"; 
  else  
  {  
    echo "You searched for <b>$search</b><br /><br /><hr size='2'>";  

    //connect to database
    mysql_connect("localhost","root","");
    mysql_select_db("idoc");

    $query = mysql_query("SELECT * FROM document WHERE $search LIKE'%$find%'");
  }

 $run = mysql_query($query);

 $foundnum = mysql_num_rows($run);

 if ($foundnum==0)
    echo "No results found";
 else
 {
    echo "$foundnum results found!<p>"; 

    echo "<table border='1'>
    <th>File Reference No.</th>
    <th>File Name</th>
    <th>iShare URL</th>
    <th>Edit</th>
    <th>Delete</th>
    </tr>";
    while ($rows = mysql_fetch_assoc($run))  
    {
      echo "<tr>";
      echo "<td>". $rows['file_ref']  ."</td>";
      echo "<td>". $rows['file_name'] ."</td>";
      echo "<td><a href=" . $rows['url'] . ">" . $rows['url'] . "</a></td>";
      echo "<td><a href=edit_doc.php?id=" . $rows['id'] . ">Edit</a></td>";
      echo "<td><a href=delete.php?id=" . $rows['id'] . ">Delete</a></td>";
      echo "</tr>";
    }
    echo "</table>"; 
  }
}
?>

Html Codes:

Htmak

<form id="form1" method="GET" action="search_admin.php">  
    <table>  
      <tr><td height="31" align="center" valign="middle" bgcolor="#990000"><span class="style1 style2">Search :</span></td></tr>  
      <tr><td><div align="left">Keyword :   
            <input name="search" type="text" id="search" size="40" /> in               
            <select name="field">
              <option value="file_name">File Name</option>     
              <option value="media_type">Media Type</option>  
            </select>  
          </div>  
            <input type = "submit" name="submit" value="search" />             
      </tr>  
    </table>  

Answer 1

Check that your query is working; the error message indicates that mysql_query doesn't return a valid result set.

Answer 2

You have these two lines:

$query = mysql_query("SELECT * FROM document WHERE $search  LIKE'%$find%'");
$run = mysql_query($query);  

The first runs the query in that string and returns a result resource. In the second line, you pass the result resource to mysql_query(), which takes a string as its argument. Since that can't possibly be valid, it returns false. You then try to ask how many rows are in false.

Answer 3

 $query = mysql_query("SELECT * FROM document WHERE $search  LIKE'%$find%'");
 //echo out construct  

 //this is setting run to, apparently a boolean, because you pass in the query result instead of a string
 $run = mysql_query($query);  

 //now you're passing a boolean into mysql_num_rows()
 //$foundnum = mysql_num_rows($run);  
 // instead try:
 $foundnum = mysql_num_rows($query);  

I think thats the problem...

Answer 4

One problem I can see is that you connect to DB and construct the query only when this condition
if (strlen($search)<=1) is false.

What if that condition is true? In that case you don't construct the query but you still go ahead run an empty query. You need to fix that.